Recent Work on the Bryopyhta. 271 
Before proceeding to the consideration of the literature on the 
morphology and biology of the Musci, and on the ecology of Bryophyta 
in general, mention may be made of some of the more extensive 
works recently published in Systematic Bryology. The first volume 
of Muller’s section on the Hepaticae in the new edition of Rabenhorst’s 
“ Kryptogamenflora ” has recently appeared ; when completed, this 
will undoubtedly be the best general account of the European 
liverworts, containing descriptions and (in most cases) figures of 
the species, while greater attention is given to biology and phylogeny 
than in any previous floristic work of equal scope on these plants. 
Other systematic publications still in progress are Stephani’s great 
work on the Hepaticas, in which are given diagnoses of all the known 
species of the world; Schiffner’s invaluable series of exsiccata of 
European liverworts, with the accompanying critical descriptions; 
Roth’s truly stupendous attempt to describe and figure in detail 
from actual specimens all the known species of mosses, as a sequel 
to his similar work on the European species ; and various moss 
exsiccata which are being issued. Of special importance to British 
students of Hepaticae is the appearance of Macvicar’s systematic 
work (23), which has just been published, containing descriptions and 
figures of all the species of Hepaticae found in the British Isles; a 
review of this important work will appear later in these columns. 
One of the most important systematic bryological works of 
recent years is that of Warnstorf (45) on the Sphagnaceae. This 
great work, which has occupied the author for six years and which 
is the fruit of his long labours on this difficult and important genus, 
is divided into a general part and a special part. In the former, 
there is given an account of the progress of sphagnology during the 
last century, with an extensive bibliography, followed by a general 
account of the morphology, biology, and geographical distribution 
of the peat-mosses. In the special (systematic) part the whole of 
the known species (350 in number) of Sphagnum are described, with 
figures of leaf and leaf-sections in practically every case ; with very 
few exceptions the author of this great monograph has examined 
all the species described. This work is of fundamental importance, 
not only for specialists in bryology but also for workers on the 
ecology of areas where the peat-mosses form a conspicuous element 
in the vegetation. It is not to be expected that all systematists 
will agree with the details of Warnstorf’s classification, which has 
been subjected to severe criticism by Roll and other writers. One 
of his recent critics (1) points out that Warnstorf is frequently led 
into error through insufficient consideration of the work of other 
botanists and unreliability in observations involving minute details, 
but such lapses do not to any serious extent detract from the value 
of his latest and greatest work nor from his claim to rank as the 
leading authority on the Sphagna. 
The phylogeny of the Musci has recently been discussed in an 
important work by Loeske (20), which is devoted to criticism of the 
methods and schemes of classification hitherto adopted by systematic 
bryologists. Loeske’s book, which is indispensable to all students 
of the Musci and of Bryophyta in general, is likely to exert great 
influence on future work in this field. The author’s own researches 
have shown that in many cases, especially among Sphagna and 
aquatic Hypnacese, mere habitat forms have been described as 
